Power semiconductor modules, as semiconductor devices, including one or two or more power semiconductor elements (semiconductor chips) embedded in a case the interior of which is sealed with a sealing material are known. For power semiconductor modules used for inverter circuits among others, switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and passive elements such as FWDs (Free Wheeling Diodes) are used as the semiconductor elements.
FIG. 11 illustrates one example of conventional power semiconductor modules.
Power semiconductor elements, as semiconductor chips 105 based on silicon or silicon carbide (SiC), are mounted on and bonded by solder or the like to a circuit plates 106c of an insulating substrate 106. The circuit plates 106c of the insulating substrate 106 include a wiring pattern formed thereon which configures an electric circuit. An electrode formed on the upper surface of the semiconductor chip 105 of the power semiconductor module 100 is electrically connected to the circuit plate 106c by bonding wires 107 made of aluminum, and terminals 141, 142, and 143 are bonded to the circuit plates 106c by welding or soldering. Copper leads (conducting plates) may be used for the electrical connection in place of the bonding wires 107.
When the electric circuit is configured by a plurality of power semiconductor chips mounted on the insulating substrate, wiring patterns of the circuit plate of the insulating substrate tend to be complicated. In addition, since the number of bonding wires increases which electrically connect an electrode formed on the upper surface of the power semiconductor chip to the circuit plate or the like, the power semiconductor module is likely to be large owing to a longer time required for the bonding and the increase in the area of regions to be wired.
A power semiconductor device is disclosed which includes, in order to miniaturize the power semiconductor module, an external terminal one end of which is exposed outside the case and the other end of which is bonded, in the case, to a circuit pattern different from a circuit pattern surmounted by a power semiconductor chip and is connected to the power semiconductor chip by a bonding wire (Patent document 1).
Further, a power semiconductor device is disclosed which includes a resin block which is integrated, by using resin, with a plurality of main terminals interposing insulation layers and is placed on a heat-dissipating plate in such a way that the block bisects the heat-dissipating plate in the case, and also includes a power semiconductor chip connected to the main terminal of the resin block by a bonding wire (Patent document 2).
Still further, a power semiconductor module is disclosed which includes a plurality of electrode-leading terminals supported by a terminal-supporting resin which has a first crossover portion and a second crossover portion, the first crossover portion being disposed, in the resin case, in such a way that it cross the resin case from a central portion on one edge of the resin case to that on the opposite edge thereof, and the second crossover portion extending from the central portion to the both sides, of the first crossover portion, wherein a semiconductor switching element is bonded to each of four spaces inside the resin case divided by the first and second crossover portions, wherein the first electrode-leading terminal is wire-bonded to a wiring pattern connected to the semiconductor switching element, and the second electrode-leading terminal is formed on the surface of the semiconductor switching element and wire-bonded to the electrode (Patent document 3).